Fix NVIDIA FPS cap profile binding

[PrimeBuild-pc]

Summary

• Fixes the NVIDIA FPS cap path so newly created DRS profiles are bound to the target executable before writing the FPS cap setting.
• Updates profile lookup to try the full executable path first, then fall back to executable name.
• Keeps FPS cap readback read-only and avoids creating profiles when clearing a cap.

Verification

• dotnet build LightCrosshair.sln
• dotnet test LightCrosshair.sln

Both passed locally with 0 warnings/errors and 165 tests passed.

Notes

This is intentionally a minimal bug fix. It does not add new NVIDIA Profile Inspector features, DLSS/Low Latency/VSync controls, updater changes, packaging changes, or version changes.